Battery.



C. F. BURGESS.

BATTERY.

APPH CATION FILED SEPT- la; l9|4- I Patented Jan. 2, 1917.

WITNESSES l/VVE/V TOR m; tfiarlesffiuyess k l y A TTOR/VEY I T TES PATENT am- TOBIES, A'CORPORATION OF WISCONSIN.

Specification of Letters Patent. 7

BATTERY.

Patented Jan. a, 1917.

original'application filed December. 10, 1913, Serial No. 805,675. Divided and this application filed September I v 18, 1914. Serial No. 862,284. a

To all whom may concern Be it known that I, CHARLES F, BURGESS, a,

citizen of the United. States, residing at Madison, county of Dane, Stateof Wisconsin, have invented certain-new and useful Improvements in Batteries; and I do hereby declare the following to be a full, clear, and

exact description of the invention,-such as will enable others skilled in the art to which it appertains to make and'use the same.

The present invention relates to dry batteries of the Leclanch type, wherein one electrode is of zinc and the other is of carbonaceous material, and theelectrolyte consists of a solution of ammonium chlorid,

' with zinc chlorid added as desired, and

wherein a solid depolarizing material is present at one electrode to oxidize the hydrogen there set free.

It is the'object of the present invention to tlons are taken.

increase the efliciency and capacity oi? such batteries, and more particularly to improve them in such a way as torobtaln'larger cur- I rent output, quicker recovery, better inter-' -nal conductivity, andgreater reliability. As

contributing to these ends, and as an important factor in obtaining the results desired, I make use of a new depolarizing mixture containing carbonaceousmaterial and a manganese depolarizer, the carbonaceous material being in graphitic form and in an extremely fine state of subdivision, and the manganese depolarizer being of" such charaeter as to cooperate to good advantage with tones of lat this graphite.-

In the accompanying drawing, forming art of this specification, there is illustrated ,m enlarged cross-section a battery or cell built in accordance with my present inven tion.- This particular cell is of the minia-c ture' Ysu1ted'for use with portable hand lamps, ut my invention can be used in bat-- r size, such as those coml'umily major te ephone and 'tion work.

" In-the drawing, the cc 1 comprises a zinc container 1' of usual construction within I .i which is a carbon rod 2 with a brass termi larizing mixture may be and preferably is cap'3, this rod bein closely enveloped by a'tightl compressed b ock 4 of depolarizing mixturg Enveloping the block 4 of deporapid self deterioration,

an envelop 5 'ofbibulous material, such as cloth gauze, which may he slipped over the block 4 after the latter has been tightlycompressed about its carbon rod 2. A winding 6 of thread or "string may hold the envelop in the form of a bag gathered together and tied tightly about the carbon rod at 7.

To prevent local action by the close proxximity of the depolarizing mixture with the CmLES E BURGESS, OF MADISON, WISCONSIN, ASSIGNOR T0 C. F. BURGESS LABORA- the graphite, by migration or otherwise, will a pass over to the zinc surface and so cause The finer the graphite, the greater is theliability to trouble from this cause unless special precau- To assemble the cell, the carbon rod 2 with introduced into the zinc container until it rests on the bottom thereof, and a paste 9 is poured in to fill the annular space between the envelop and the zinc container. Prefer.- ably a starch water paste is used, containing ammonium chlorid and zinc chlorid in such proportions that upon standing for a few minutes the paste g elatinizes and becomes semi-solid.

The starch paste is poured in until it comple'tely covers the top of'block 4; and above the top of the starch paste, with an air gap 10 intervening, is' introduced a paraflin washer 11 above which the cell. is filled up with a pitch seal 12 substantially to the top,

projecting upwardly through the pitch, so

that contact may be established with the external circuit.--

' The depolarizing mixture whereon the improved action of this cell is largely dependent, consists of carbonaceous material and a manganese depolarizer, andalso may contain, the usual electrolyteiorming salts, such as sal ammoniac and .zincchlond, together:

with the necessary water.

\ The quality of the carbonaceous material is a vital factor in the operation of the bat:

tery of my invention, and although the characteristics of the material which is used are somewhat diflicult of definition, and the reasons for the advantageous results are m some respects'obscure, nevertheless the d1sclosures hereinafter made will enable those \skilled in the art to construct such batteries. The carbonaceous material used by me is graphitic in character, and for a complete understanding of its character1st1cs and 1ts relation to various kinds of graphite heretofore used, it is desirable to set forth herein some of the distinguishing characteristics of various kinds of graphite. In the following '15 table appear data of ten kinds of graphite together with anenumeration of their respective characteristics. These various-materials were obtained from the International Acheson Graphite Company of Niagara Falls, and are designated by their trade numbers Electrical Relative Relative t Fineness. g fi resist- I volume volume ance. dry. in water.

92 7. 20 160 935 3. 2 $3 2. 61 087 93 3. 2 96 4.46 .160 1.0-5 3.4 99.5 .77 .115 1.38 4.6 99.5 i .00 .128; 1.34 5.3 88 3.50 .135 .915 3.5 575 1 88' Ii iii 5:2 A3 impalpable. 9. 55 568 2. 18 14. 5 750 i 6. 3O 434 1 2. 28 14. 8

In the above table the fineness is expressed in the percentage of material which will pass through a sieve with 200 meshes per lineal inch, a standard method of'grading. The ash is determined by ordinary methods of analyses. The electrical resistance is ['40 measuredwith the dry material held iii a tubular cylinder one inch in diameter and there subjected to. a pressure of twenty pounds between two graphite electrodes.

By measuring the electrical resistance of the material held between two electrodes} the values given in the above table were determined and are expressed in ohms per lineal inch of column one inch in diameter.

The relative volume dry is determined by placing ten grams of graphite in a cylinder one inch in diametei-and tapping the container until the material settles to a con stant volume. The figures in the above table indicate the height in inches occupied by the ten grams of graphite.

The relative volume in water as given in the above table is determined by placing one gram of graphite in a 25 cubic centimeter graduated glass cylinder having an internal diameter about 11/16, addingwater so that the total volume is 25 cubiccentimeters and allowing the graphite to settle for one hour. The apparent volume of the settled graphite is then measured on the graduated scale and es the figures in the above table indicatein graphite which are cubic centimeters the volume occupied by one gram of graphite after settling forone hour in 25 cubic centimeters of water.

Of the several grades of graphite appearing in the table the first seven are listed by .the International Acheson Graphite Company-as being battery grades, andthe first two are the grades which have been in most general use in this country for the manufacture of standard size of dry batteries. The last two grades are the kind used by me in accordance with this invention. By refere'nce to the table it will beseen that these That is the term under which finer than even those grades of Acheson graded by passing through a 200 mesh sieve. This impalpable grade may be further distinguished by its light flufl'y character, which gives it great bulk as compared with some of the coarser grades and which gives to it an apparently low specific gravity. The great difi'erence in the fineness of the impalpable graphite and that of the 200 mesh graphite heretofore used can be readily detected, by means of a high power microscope. It is difiicult, if not impossible to give the exact dimensions of the particles but it is my present belief that they are less than of an inch in diameter. The difference can better be'detected by the method of settling out of, water in the manner indicated for determining the figures in the last column of'the above table. From this it isseen that the volume occupied by the impalpable powder is from three to five times that occupied by the commonly usedgrades.

1 By'reference to the-above table it will be seen that the electrical resistance of the graphite used by me is approximately four times that of graphites as heretofore used: Tt'is not certain that this is a characteristic" of thegraphite itself but maybe due to its extremeof contacts'presented to the flow of current when the resistance measurement is made with the graphite dried and under pressure. High resistance has heretofore been gener- .allyaccepted as indicating inferiority in graphite for battery use, but. withmy materials T have found that, in spite of this apparent inferiority as regards resistance the impalpable aphite possesses striking advantageous' c aracteristics which ll have discovered and which make it possible to impart desirable qualities to dry cells by its use.

fineness and to the greater number i I of recovered manganese.

or recovered manganese from any one of several difi'erent sources as claimed herein. Artificial manganese is obtainable as a byproduct from several different industrial processes, such as the manufacture of chlorin, and bleaching powder, and saccharin, and in this country has been marketed for many years under the name recovered manganese by chemical houses.

In using any one of the several kinds ,or grades of manganese depolarizer it is advis-' able to recognize its particular individual characteristics and to "control the proportions of the mix and other details to meet the needs of that particular depolarizer. Among those'important characteristics of the manganese depolarizer are (1) density, (2) fineness, (3) degree of hydration." Pyrolusite has a greater density than the other forms of manganese and requires a smaller percentage by weight of" the impalpable graphite than do other forms of manganese of a lower specific gravity. A suitable mixture may be made in the proportions of 100 grams impalpable graphite, 21 grams pyrolusite, 13 grams ammoniumchlorid, and 15 grams water.

The pyrolusite as supplied on the market is much coarser than are the various grades A common-degree of fineness of pyrolusite is thatvdefined as material which. passes through a 40 mesh screen. Recovered manganese, being formed by a chemical precipitation process, consisting of much more minute particles than those whichjust pass through such a screen, and the relative degree of fineness hasmuch to do with the relative proportions of impalpable graphite which'mustbe added to produce the best results. r

As to degree of hydration, this is less in pyrolusite than in artificial or recovered manganese in general, and since with the use of pyrolusite it is only the hydrated 'ma-.

terial which participates in the depolarizing action (though some of the unhydrated may become hydrated by secondary action, and later become available for delivering oxygen to combine with,the hydrogen resulting from the flow of current) the proportion o .pyrolusite, weight for weight, should be greater than when the more highly hydrated depolarizers are used. For instance, using a standard grade of recovered manganese,'a

suitable mixture is as follows: 12 grams impalpable graphite, 30 grams recovered manganese, 3.5 grams ammonium chlorid, 3.3 grams zinc chlorid, 12 grams water.

Throughout the scientific literature relating to Leclanch cells the term manganese is freely used to designate pyrolusite, which is manganese dioxid MnO partially hydrated. In elementary text books the chemistry of depolarization is commonly said to result from the chemical union of the electrolytic hydrogen with oxygen given up by' the manganese dioxid, but for several years it has been recognized by electro-chemists that the reaction is more complex than this and involves the union of hydrogen with the 4 OH radical of the pyrolusite or other manganese depolarizer, necessitating therefor the presence of manganese oxid in a hydrated form, such as is present in pyrolusite, (and even in the ore before washing and grinding), and such as is present in the various kinds of recovered manganese now obtainable on the market.

W'ithout desiring to be limited by any particular theory for the cause of the beneficial effects which I have been able to produce as above described, one explanation may be presented as follows. parently high resistance of the impalpable graphite, it gives excellent characteristics to the mix which goes into the dry cell construction, partly by flowing readily into interstices between the manganese particles, thereby forming a more homogeneous and continuous path for the flow of current to the carbon rod, than would be the case were graphite in largerparticles employed, and partly by the increased effectiveness of the depolarizer when the materials are in this most intimate contact.

In spite of the ap- The conductivity of graphite, even the impalpable forms, is of such a high order as compared with the conductivity of pyrolusite or of recovered manganese (about in the relation of 10,000 and over to one) that the graphite must be relied upon entirely as the conducting medium for the flow of curmeasurements of graphite is from 3,500 to- 10,000 ohms r lineal inch, or a conduc-" tivity less than 1/10,000 of that'of graphite.

Recovered manganese in its more common forms has even less conductivity, and by the above designated mode of resistance measurement a typical material which has been extensively employed by me has a resistance of;136,000 ohms per. linealinch, or a conductivity less than 771% that of the im-' palpable graphite and less than 7, that of pyrolusite.

The effectiveness of depolarizing material is de endent upon the intimacy of its contact with the conductive graphite, and this intimacy of contact is greater Where the impalpable graphite is used than where the coarser grade is employed. The capacity of a dry cell for delivering current is determined, in a measure, by the amount of water which the depolarizing mixture will hold. This amount of water is greater with the use of the impalpable graphite than with the use of the coarser grades, as is evidenced by the greater. absorption of water which the impalpable material possesses.

The above disclosure sets forth all of the data necessary to enable those skilled in the art to practise my invention, irrespective of the origin of the manganese depolarizer, and whether pyrolusite is used or the more finely divided recovered manganese. It has been found inpractice that the recov ered manganese varies somewhat in purity depending upon its origin, and it is good practice in preparing it for the battery to wash it with water and so take out any soluble impurities that may be present, after which the residue may be dried and put into such physical condition that it may be readily mixed with the other ingredients.

In the commercial manufacture of batteries according to my process, the impalpable graphite has been obtained from the International Acheson Graphite Company, it being a secondary product resulting from their methods of air separation.

I claim:

1. In a drybattery, the combination of a zinc container, acarbon rod supported therein, a depolarizing mixture inclosing said rod and consisting essentially of impalpable graphite and manganese dioxid together with theusual salts and water, and a gelatinized paste separating said depolarizing mixture from the zinc container and effectively preventing transference of the impalpable graphite into physical contact with the zinc, substantially as described.

2. In a dry battery, the combination of a zinc container, a carbon rod supported therein, a depolarizing mixture inclosing said rod and consisting essentially of impalpable .graphite and manganese dioxid together with the usual salts and water, and an envelop inclosing said mixture, the lower end of said envelop and of the mixture being impregnated with paraffin and preventing the impalpable graphite from passing over to the adjacent zinc surface by migration or otherwise, substantially as described.

3. In a dry battery, the combination of a zinc container, a carbon rod supported therein, a depolarizing mixture inclosing said rod and consisting essentially of impalpable graphite and recovered manganese together with the usual salts and water, a cloth envelop for said mixture, the lower end of said envelop and of the mixture being impregnated with paraffin, and a gelatinized paste between said container and said envelop, substantially as described.

4. In a dry battery, the combination of a zinc container, a carbon rod supported therein, a depolarizing mixture inclosing said rod and consisting essentially of impalpable graphite andrecovered manganese, a cloth gauze envelop for said mixture and a gelatinized paste separating said depolarizing mixture from the zinc and effectively preventing movement of the impalpable graphite through said gauze envelop, substantially as described.

In testimony whereof I aflix my signature, in presence of two witnesses.

CHARLES F. BURGESS.

\ Vitnesses:

A. O. OLMAN, J. B. RAMSEY. 

